<!DOCTYPE html>
<html>
<head>
<style>
.box {
    height: 200px;
    width: 200px;
    margin: 10px;
}

.gradient1 {
    background: radial-gradient(5em circle at left 55px bottom 75px, yellow, blue);
}

.gradient2 {
    background: radial-gradient(5em circle at top 65px right 45%, yellow, blue);
}

.gradient3 {
    background: radial-gradient(5em circle at bottom 65px right 45%, yellow, blue);
}

.gradient4 {
    background: radial-gradient(5em circle at center left 45%, yellow, blue);
}

.gradient5 {
    background: radial-gradient(5em circle at right 45% center, yellow, blue);
}

.gradient6 {
    background: radial-gradient(5em circle at right calc(60px + 5px) center, yellow, blue);
}

</style>
</head>
<body>
    <div class="gradient1 box"></div>
    <div class="gradient2 box"></div>
    <div class="gradient3 box"></div>
    <div class="gradient4 box"></div>
    <div class="gradient5 box"></div>
    <div class="gradient6 box"></div>
</body>
</html>